Outboard motor



Aug. 111, 1936. l R. KARAslNsKl OUTBOARD MOTOR Original Filed April 27, 19254 rammed Aug'. 11', 1936 lParent oFrl-clez ou'rnoann Moron i Romuald Karasinslxi,

Johnson Motor Company, corporation of Delaware Waukegan, Ill., assignor to Waukegan,l lll., a

ltellled for` abandoned yapplication Serial No. 722,721, April 27, 1934. This application Deceinbcr 23, 1935, Serial No.

5 Claims.

ingly, it is often desirable to operate the boatl at a very low rate of speed, as for shing or trolling, and a principal object of the present invention is to produce a simple and inexpensive device which is attached to the outboard motor for operating it and a boat to which it is connected at a low rate of speed.

Another object oi' the invention is in the provision of a movable trolling plate which is automatic in its action, depending upon the force exerted by the propeller to raise it from trolling position.

A further obect ci the invention is in the provision of a trolling plate which -is adapted for use in connection with outboard motors having an underwaterI exhaust.

A still further object of the invention. is in the provision oi a trolling plate which has curved portions for producing greater rigidity/and for stabilizing the motor in its use while running'.

`(Zither objects ot the invention will appear hereinafter, the preferred construction being illustrated in the accompanying drawing. In the drawing, Fig. l isla side elevation ci the lower driving unit and propeller of an outboard motor driving unit to which the` present t invention is applied;

' ing, a lower drive 2 is a plan view o the trollingplate; and

Fig. 3 is a section taken on the line 3-3 ci `Trolling platesoi various kinds have been used with boats and also with outboard motors but the present one'is attached directly at the rear ci an.anticavitation plate lwhich is formed integral with the lower driving casingof an outboard motor and provision is made for discharging the underwater exhaust from the motor through the upper edge of the trolling plate when it is in a retardlng positionfor otherwise the exhaust discharge would be nearly closed and the exhaust lgases would be directed toward the propeller thereby tending to produce slippage and racing of the motor.

Referring now more unit only of an outboard motor is shown in Fig. 1 having a smooth walled casing 5 above and below anLanti-cavitation plate I. A lower enlarged portion] for seating the particularly to the draw- (Cl. 11S-17) driving mechanism (not shown) for a propeller 8 disposed below and toward the rear of the antl-cavitation plate 6 and having portions arching the upper edge of the path of travel o! the propeller blades and providing an inlet 9 at the 5 rear "of the propeller for receiving water thrust rearwardly thereby and a discharge opening I0 in advance of thegpropeller to withdraw water from a passagewithin the casing thereby causing a. circulation of cooling water to the engine, 10 which, however, forms no part of the'present invention.

Also within the casing E and at the` rear thereof is an exhaust passage ll which extends f through the rear of the anti-cavitation and has a discharge opening l2 below the anticavitatlon plate and in the propeller race for discharging the exhaust gases from the engine at the rear of the motor and below water level. The above construction is common with 20 motors of this type with the exception that the anti-cavitatlon' plate il terminates closely adjacent the rear edge oi the casing in a pair of spaced ears i3 and a trolling plate llt has corresponding ears le through which a hinge rod it is inserted with a spring il mounted on the rod between the ears i3 and having opposltely extending extremities4 it engaging the plate i@ and the plate il and tending lto turn the trolling plate ld downwardly to the position shownin Fig. l. The trolling plate ls provided with projections t@ tor engaging the underside of the Vanti-cavitation plate t and limiting the downward movement oi the trolling plate ld so that it will be clear of engagement with the' propeiler 6.

in the central upper portion or the trolling plate It is an opening 2illocatedydirectly baci; of the opening l2 for the exhaust gases so that even when the plate is in the downward position as shown in Fig. l, the exhaustv gases are discharged, freely into the water below the anticavitation plate (i. This opening 2B is ci greater extent than the-actual'discharge opening l2 so position, ample opening will be afforded through the plate i4 for lthe discharge of the exhaust gasesl therethrough.

It is important that the trolling plate be both I light and strong and .it is preferably formed or cast in a thin sheet .with curved portions 2| `extending outwardly from the center and facing downwardly or inwardly toward the motor casing when in a lowered position so that the trolling Y plate will have a tendency to stabilize the motor 55 plate 6 15 I in its movementl through the water, the curved portions also tending to guide the water from f the propeller outwardly from the trolling plate when it is in lowermost position.

This trolling plate is automatic in operation, dependent upon the pressure of the spring l1 and the driving power of the propeller. Witha y proper spring tension the trolling plate will be forced downwardly until the stops I9 engage the underside of the anti-cavitation plate when the propeller 8 is being driven at slow speed. When the speed, and consequently the power of the propeller, is increased, the tension of the spring I'I will be overcome and the trolling plate I6 will be raised depending upon the power of the propeller until the trolling plate may reach a position in which it is substantially parallel or forms a substantial continuation of the anti-cavitation plate 8 as represented in the broken outline as shown in Fig. 1. Thus the action of the trolling plate is entirely automatic and no manual attention need be given thereto while it is in operation.

To operate the plate for trolling, the speed ofI .the engine is simply cut down, whereupon the spring Il turns the trolling plate downwardly and if the operator of the motor wishes to drive the boat more rapidly he simply speeds up the engine, which increases the driving power and raises the trolling plate in accordance therewith. The trolling plate thus retards the boat or augmenta the function of the anti-cavitation plate 6.

This application is a rele of my abandoned application Serial No. 722,721, illed August 27, 1934.

I claim:

1. In an outboard driving unit having a casing with an underwater exhaust and a driving propeller, a trolling plate hinged to the casing and movable from a position at the back of the propeller to a position at an angle thereto, the underwater exhaust opening being located adjacent the upper edge of the plate, and the plate having an opening in the upper portion thereof opposite the said discharge opening to admit the exhaust therethrough regardless of the position or the plate.

2. A trolling plate for an underwater exhaust, the plate being provided with means for hinging it to the rear of the unit and haying an opening adjacent its upper edge through which the exhzust may pass regardless oi' the position of the p ate.

3. A marine propulsion device comprising the combination with a propeller and a support therefor, of a plate pivoted to said support and provided with stop means limiting its pivotal movement to a range from an upright position iml right rst position, said plate mediately behind the propeller to an approximately horizontal position immediately above the propeller slip stream, said plate being freely oscillatable within said range, and means suppleinenting the action oi gravity on said plate for biasing said plate toward its said upright position, said plate being substantially symmetrical and centered behind said propeller, whereby in its upright position it will intercept the propeller slip` stream without materially affecting the course oi a craft propelled.

4. A marine propulsion device comprising the combination with a propeller and a support therefor, of a plate having means pivotally connecting it with said supportand providing for the free movement of said plate through a range from c. substantially upright position immediately behind the propeller to a second position substantially parallel to the propeller slip stream, stops limiting the movement of said plate beyond said first position, and a spring biasing said plate ior movement toward said first position, said plate being subject to the action of propeller slip stream thrust in opposition to said spring for thrust responsive movement about its ulcrum in said range, the strength of said spring being predetermined with reierence to the thrust exercised by the propeller slip stream at low and high propeller speeds in a relation such that the spring will overcome ythepropeller slip stream thrust at low propeller speeds and maintain said plate in said upright position, and l the propeller slip stream thrust will overcome the spring at higher propeller speeds and i'orce said plate toward its said second position.

5. A marine propulsion device comprising the combination with a propeller and a support, of a horizontal pintle connected with the support above the propeller, a plate iulcrumed upon the pintle and having its lower portion movable across the propeller slip stream to a substantially upbeing also freely movable about said pintle to a substantially horizontal position in which said position is outside of the propeller slip stream, and a spring biasing said plate for movement toward said first position and suiiiclently strong to overcome the action of the propeller slip stream upon said plate at low propeller speeds, said spring being suiiiciently light in its pressure upon said plate to permit/50 said plate to yield to the thrust of the propeller slip stream as the speed of the propeller is increased nd to remain completely out of said propeller slip stream throughout a substantial range oi cruising speeds of the propeller.

ROMUALD I An en 'un 

